From 73fa48b674e819098c3bafc47618d0e2868191e5 Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Tue, 29 Sep 2015 20:50:33 -0700 Subject: [PATCH] Btrfs: refactor caching_thread() We're also going to load the free space tree from caching_thread(), so we should refactor some of the common code. Signed-off-by: Omar Sandoval Signed-off-by: Chris Mason --- fs/btrfs/ctree.h | 3 +++ fs/btrfs/extent-tree.c | 59 ++++++++++++++++++++++++++++---------------------- 2 files changed, 36 insertions(+), 26 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 42c41dc..60df67e 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1262,6 +1262,9 @@ struct btrfs_caching_control { atomic_t count; }; +/* Once caching_thread() finds this much free space, it will wake up waiters. */ +#define CACHING_CTL_WAKE_UP (1024 * 1024 * 2) + struct btrfs_io_ctl { void *cur, *orig; struct page *page; diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 601d7d4..af8ffb5 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -375,11 +375,10 @@ static u64 add_new_free_space(struct btrfs_block_group_cache *block_group, return total_added; } -static noinline void caching_thread(struct btrfs_work *work) +static int load_extent_tree_free(struct btrfs_caching_control *caching_ctl) { struct btrfs_block_group_cache *block_group; struct btrfs_fs_info *fs_info; - struct btrfs_caching_control *caching_ctl; struct btrfs_root *extent_root; struct btrfs_path *path; struct extent_buffer *leaf; @@ -387,16 +386,15 @@ static noinline void caching_thread(struct btrfs_work *work) u64 total_found = 0; u64 last = 0; u32 nritems; - int ret = -ENOMEM; + int ret; - caching_ctl = container_of(work, struct btrfs_caching_control, work); block_group = caching_ctl->block_group; fs_info = block_group->fs_info; extent_root = fs_info->extent_root; path = btrfs_alloc_path(); if (!path) - goto out; + return -ENOMEM; last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET); @@ -413,15 +411,11 @@ static noinline void caching_thread(struct btrfs_work *work) key.objectid = last; key.offset = 0; key.type = BTRFS_EXTENT_ITEM_KEY; -again: - mutex_lock(&caching_ctl->mutex); - /* need to make sure the commit_root doesn't disappear */ - down_read(&fs_info->commit_root_sem); next: ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); if (ret < 0) - goto err; + goto out; leaf = path->nodes[0]; nritems = btrfs_header_nritems(leaf); @@ -446,12 +440,14 @@ next: up_read(&fs_info->commit_root_sem); mutex_unlock(&caching_ctl->mutex); cond_resched(); - goto again; + mutex_lock(&caching_ctl->mutex); + down_read(&fs_info->commit_root_sem); + goto next; } ret = btrfs_next_leaf(extent_root, path); if (ret < 0) - goto err; + goto out; if (ret) break; leaf = path->nodes[0]; @@ -489,7 +485,7 @@ next: else last = key.objectid + key.offset; - if (total_found > (1024 * 1024 * 2)) { + if (total_found > CACHING_CTL_WAKE_UP) { total_found = 0; wake_up(&caching_ctl->wait); } @@ -503,25 +499,36 @@ next: block_group->key.offset); caching_ctl->progress = (u64)-1; +out: + btrfs_free_path(path); + return ret; +} + +static noinline void caching_thread(struct btrfs_work *work) +{ + struct btrfs_block_group_cache *block_group; + struct btrfs_fs_info *fs_info; + struct btrfs_caching_control *caching_ctl; + int ret; + + caching_ctl = container_of(work, struct btrfs_caching_control, work); + block_group = caching_ctl->block_group; + fs_info = block_group->fs_info; + + mutex_lock(&caching_ctl->mutex); + down_read(&fs_info->commit_root_sem); + + ret = load_extent_tree_free(caching_ctl); + spin_lock(&block_group->lock); block_group->caching_ctl = NULL; - block_group->cached = BTRFS_CACHE_FINISHED; + block_group->cached = ret ? BTRFS_CACHE_ERROR : BTRFS_CACHE_FINISHED; spin_unlock(&block_group->lock); -err: - btrfs_free_path(path); up_read(&fs_info->commit_root_sem); - - free_excluded_extents(extent_root, block_group); - + free_excluded_extents(fs_info->extent_root, block_group); mutex_unlock(&caching_ctl->mutex); -out: - if (ret) { - spin_lock(&block_group->lock); - block_group->caching_ctl = NULL; - block_group->cached = BTRFS_CACHE_ERROR; - spin_unlock(&block_group->lock); - } + wake_up(&caching_ctl->wait); put_caching_control(caching_ctl); -- 2.7.4